* feat(platform): resolver core with locate/inspect/probe tiers and ordered candidates
Every resource lookup needs one result shape and one cost contract. `locate` reads
metadata only, `inspect` may open files and call OS APIs in-process, `probe` is fresh
and the only tier that may spawn or connect. `Resolution.candidates` keeps probe order
so fan-out consumers can try every present binary.
Linear NS-921.
* feat(platform): AppResolver over AppDef with plist, PE, registry, and server.json sources
Desktop apps need presence, version, and liveness as separate observations. The runtime
file's bearer token is parsed, used for one request, and discarded inside the probe;
no public type carries it. Endpoints are accepted only when loopback with a numeric port.
* refactor(copilot): gh candidates through locate_command and the Homebrew table
First consumer of the resolver. The gh token probe still tries every present binary in
order; the allowlist loses its two copilot_auth rows.
* feat(platform): availability() over an application declaration
locate() + inspect() only, never probes; the fail-closed _version in
app.py treats a vendor's plist/PE/registry entry as untrusted input.
Salvaged from PR #118122; reads any object with requires_app,
min_version, app_for(os) — nothing here imports the MCP catalog.
* feat(platform): application declarations parsed into AppDef per OS
The parser slice of PR #118122's catalog manifest, re-homed as a
catalog-free module: whoever owns an MCP server declares the app it
fronts per OS and what it needs, and registers it here. Stdlib +
hermes_platform.resolver only. register/lookup/clear are the one seam
the MCP check_fn and the skill gate both read.
* feat(mcp): check_fn honours a registered application declaration
_make_check_fn ANDs the declared app's availability into the
connection-alive check; with nothing registered for the server the
behaviour is the pre-PR3 connection check. Provenance is explicit
registration, not endpoint matching. Returns a plain bool: the registry
caches bool(fn()).
* feat(skills): requires_apps gate through registered declarations
Offer-time filter beside environments:; names resolve through
hermes_platform.declaration, an unknown name hides the skill (fail
closed). The disk snapshot carries requires_apps and the fast path
re-evaluates it (snapshot version bumped to 3): app presence is a host
fact that changes without SKILL.md changing.
* docs: application declarations page
The plugin-facing schema reference: app: and requires: blocks,
availability() states, and the two gates that read the registry.
Registered under Extending > Plugins in the docs sidebar.
* test(platform): declaration parser, availability, gates
The PR3 app-block tests re-homed off the catalog: fixtures are dicts
passed to parse_declaration, the check_fn gate keys on explicit
registration (not endpoint matching), and the import-hygiene probe now
covers hermes_platform.declaration and resolver.availability.